Spectral-spatial imaging device

Abstract

In general, an imaging system to synchronously record a spatial image and a spectral image of a portion of the spatial image is described. In some examples, a beam splitter of the imaging system splits an optical beam, obtained from a viewing device, into a first split beam directed by the imaging system to a spatial camera and a second split beam directed by the imaging system to the entrance slit of an imaging spectrograph that is coupled to a spectral camera. An electronic apparatus synchronously triggers the spatial camera and the spectral camera to synchronously record a spatial image and a spectral image, respectively.

What is claimed is: 
     
       1. A spatial-spectral imaging apparatus comprising:
 a beam splitter configured to receive a light beam carrying an image of an object and to split the light beam into a first split light beam and a second split light beam; 
 an imaging spectrograph configured to receive the first split light beam and disperse a range of wavelengths of the first split light beam to form a spectral image comprising a plurality of spectra; 
 a spatial image camera configured to receive the second split light beam; and 
 a spectral image camera configured to receive the spectral image from the imaging spectrograph, 
 wherein the spectral image camera and the spatial image camera are configured to synchronously record, respectively, the spectral image to generate a recorded spectral image of the spectral image and a spatial image carried by the second split light beam to generate a recorded spatial image of the spatial image, the recorded spectral image comprising multiple evenly-spaced optical spectra in a defined area of the image of the object that map to corresponding points in the recorded spatial image to enable the assignment of individual optical spectra of the recorded spectral image to physical features in the recorded spatial image. 
 
     
     
       2. The spatial-spectral imaging apparatus of  claim 1 , wherein the beam splitter is configured to split approximately 70% of the light beam into the first split light beam and approximately 30% of the light beam into the second split light beam. 
     
     
       3. The spatial-spectral imaging apparatus of  claim 1 , further comprising:
 a trigger device configured to send, in response to a common trigger, the spatial image camera and the spectral image camera respective signals, 
 wherein the spatial image camera and the spectral image camera are configured to, in response to receiving the respective signals, synchronously record the spatial image carried by the second split light beam and the spectral image, respectively. 
 
     
     
       4. The spatial-spectral imaging apparatus of  claim 1 ,
 wherein the first split light beam carries a first image corresponding to the image and the second split light beam carries a second image corresponding to the image, 
 wherein the imaging spectrograph comprises an entrance slit that defines an area of the first image input to the imaging spectrograph and having light dispersed into the range of wavelengths to form the spectral image, wherein the area of the first image is the defined area of the image of the object. 
 
     
     
       5. The spatial-spectral imaging apparatus of  claim 4 , wherein the area of the first image correlates to a corresponding area of the second image. 
     
     
       6. The spatial-spectral imaging apparatus of  claim 4 , wherein each spectrum of the plurality of spectra maps to a point in the second image. 
     
     
       7. The spatial-spectral imaging apparatus of  claim 4 ,
 wherein the first image comprises: 
 the range of wavelengths for each spectrum of the plurality of spectra in a first dimension; 
 a one-dimensional image of the object in a second dimension, 
 wherein a horizon of the second image corresponds to the one-dimensional image of the object in the second dimension. 
 
     
     
       8. The spatial-spectral imaging apparatus of  claim 1 , wherein the range of wavelengths is evenly spaced. 
     
     
       9. The spatial-spectral imaging apparatus of  claim 1 , wherein the range of wavelengths comprises >30 wavelengths. 
     
     
       10. The spatial-spectral imaging apparatus of  claim 1 , wherein the range of wavelengths comprises >100 wavelengths. 
     
     
       11. The spatial-spectral imaging apparatus of  claim 1 ,
 wherein the spatial image camera is configured to generate a recorded spatial image of the spatial image, and 
 wherein the spectral image camera is configured to generate a recorded spectral image of the spectral image. 
 
     
     
       12. The spatial-spectral imaging apparatus of  claim 1 , further comprising:
 an adapter to attach the spatial-spectral imaging apparatus to a retinal viewing device configured to output the light beam carrying the image of the object. 
 
     
     
       13. The spatial-spectral imaging apparatus of  claim 1 , further comprising:
 a filter compartment for an optical filter, the filter compartment located on an imaging path of the second split light beam. 
 
     
     
       14. The spatial-spectral imaging apparatus of  claim 1 ,
 wherein the spectral image camera is configured to store first association data for the spectral image, and 
 wherein the spatial image camera is configured to store second association data for the spatial image, the first association data and the second association data usable for determining the spectral image and the spatial image were synchronously recorded. 
 
     
     
       15. An imaging system comprising:
 a retinal viewing device configured to output a light beam carrying an image of an object; and 
 a spatial-spectral imaging apparatus comprising:
 a beam splitter configured to receive the light beam carrying the image of the object and to split the light beam into a first split light beam and a second split light beam; 
 an imaging spectrograph configured to receive the first split light beam and disperse a range of wavelengths of the first split light beam to form a spectral image comprising a plurality of spectra; 
 a spatial image camera configured to receive the second split light beam; and 
 a spectral image camera configured to receive the spectral image from the imaging spectrograph, 
 wherein the spectral image camera and the spatial image camera are configured to synchronously record, respectively, the spectral image to generate a recorded spectral image of the spectral image and a spatial image carried by the second split light beam to generate a recorded spatial image of the spatial image, the recorded spectral image comprising multiple evenly-spaced optical spectra in a defined area of the image of the object that map to corresponding points in the recorded spatial image to enable the assignment of individual optical spectra of the recorded spectral image to physical features in the recorded spatial image. 
 
 
     
     
       16. The imaging system of  claim 15 , wherein the retinal viewing device comprises a fundus camera. 
     
     
       17. A method comprising:
 triggering a spatial-spectral imaging apparatus to trigger a spectral image camera and a spatial image camera to synchronously record, respectively, a spectral image and a spatial image, 
 wherein the spatial-spectral imaging apparatus comprises: 
 a beam splitter configured to receive a light beam carrying an image of an object and to split the light beam into a first split light beam and a second split light beam; 
 an imaging spectrograph configured to receive the first split light beam and disperse a range of wavelengths of the first split light beam to form the spectral image, wherein the spectral image comprises a plurality of spectra; 
 the spatial image camera configured to receive the second split light beam; and 
 the spectral image camera configured to receive the spectral image from the imaging spectrograph, 
 wherein the spectral image camera and the spatial image camera are configured to synchronously record, respectively, the spectral image to generate a recorded spectral image of the spectral image and the spatial image to generate a recorded spatial image of the spatial image, wherein the recorded spectral image comprises multiple evenly-spaced optical spectra in a defined area of the image of the object that map to corresponding points in the recorded spatial image to enable the assignment of individual optical spectra of the recorded spectral image to physical features in the recorded spatial image, and wherein the spatial image is carried by the second split light beam. 
 
     
     
       18. The method of  claim 17 , wherein the images are of an object having inherent motion not directly under the control of the user of the spatial-spectral imaging apparatus. 
     
     
       19. The method of  claim 17 , further comprising:
 associating a recorded spatial image recorded by the spatial image camera and a recorded spectral image synchronously recorded by the spectral image camera. 
 
     
     
       20. The method of  claim 19 , further comprising:
 based on the association of the recorded spatial image and the recorded spectral image, mapping a spectrum of the plurality of spectra of the recorded spectral image to a point in the recorded spatial image. 
 
     
     
       21. The method of  claim 17 , wherein the object is a human fundus of a live human subject. 
     
     
       22. The method of  claim 17 , further comprising:
 processing the recorded spectral image to compute an absorption spectrum for a patient; and 
 detecting, based on the absorption spectrum for the patient, an indication of Alzheimer's disease in the patient. 
 
     
     
       23. The method of  claim 22 , further comprising:
 identifying, based on the recorded spatial image, locations of a feature within the object; and 
 mapping the locations to one or more spectra of the optical spectra of the recorded spectral image, 
 wherein processing the recorded spectral image to compute an absorption spectrum for a patient comprise computing the absorption spectrum of the one or more spectra of the optical spectra of the recorded spectral image. 
 
     
     
       24. The method of  claim 23 , wherein the feature comprises one of an optic disc, a retinal area, or a perifovea. 
     
     
       25. A spatial-spectral imaging apparatus comprising:
 a beam splitter configured to receive a light beam carrying an image of an object and to split the light beam into a first split light beam and a second split light beam; 
 an imaging spectrograph configured to receive the first split light beam and disperse a range of wavelengths of the first split light beam to form a spectral image comprising a plurality of spectra; 
 a spatial image camera configured to receive the second split light beam; and 
 a spectral image camera configured to receive the spectral image from the imaging spectrograph, 
 wherein the spectral image camera and the spatial image camera are configured to synchronously record, respectively, the spectral image to generate a recorded spectral image of the spectral image and a spatial image carried by the second split light beam to generate a recorded spatial image of the spatial image, wherein the recorded spectral image comprises multiple evenly-spaced optical spectra along a first image dimension and a one-dimensional image of the object along a second image dimension that corresponds to a center horizon of the recorded spatial image to enable the assignment of individual optical spectra of the recorded spectral image to physical features in the recorded spatial image.